11/30/15 Ch. 17 Mechanical Waves Day 1

Objectives SWBAT explain the difference between the two MAIN types of waves SWBAT describe the anatomy of a wave and how it applies to transverse waves

A rhythmic disturbance that carries energy. (NOT MATTER!!) A WAVE is… A rhythmic disturbance that carries energy. (NOT MATTER!!)

Electromagnetic (EM) Waves Also called the Electromagnetic (EM) Spectrum DOES NOT require a MEDIUM (matter or material) to travel CAN TRAVEL through space

Mechanical Waves A rhythmic disturbance that carries energy through a medium (ex. water, air, soil and rock) MUST HAVE a MEDIUM to travel

Transverse Waves Matter travels perpendicular to the wave WAVE MOTION: up & down Ex. Water waves

Anatomy of a Transverse Wave Rest Position

Amplitude & Wave Energy Amplitude = half of the wave’s height The larger the amplitude, the more energy the wave carries.

Period, Frequency & Wavelength Wavelength (λ) = the distance between the crests or troughs on a wave Measured in metric units. (m, cm, km, etc.) Period (T) = the amount of time it takes for a wave to complete ONE cycle Measured in seconds Frequency (f) = the number of waves that pass a point in a certain amount of time, usually ONE second Measured in Hertz (Hz). 1 Hz = 1 cycle/second Wave Speed (v) = Wavelength (λ) x Frequency (f)

12/1/15 Ch. 17 Mechanical Waves Day 2

Objectives SWBAT explain the similarities difference between longitudinal and transverse waves SWBAT describe what produces each type of wave in nature

Wavelength, Frequency, & Energy https://www.classzone.com/books/ml_science_share/vis_sim/wslm05_pg18_graph/wslm05_pg18_graph.html https://phet.colorado.edu/sims/html/wave-on-a-string/latest/wave-on-a-string_en.html

Longitudinal Waves AKA compressional waves Matter travels in the same direction as the wave. WAVE MOTION: back & forth Ex. Sound Waves Transverse vs. Longitudinal Waves https://docs.google.com/file/d/0B5zuB4hPBcz8c09QeW9YMWlSMnVFT1QzTWZiTHFidw/view?pli=1

Anatomy of a Longitudinal Wave Compression: particles close together Rarefaction: particles spread apart Wavelength: from one compression to the next

Transverse & Longitudinal Waves have the same parts Transverse Wave Longitudinal Wave Crest Compression Trough Rarefaction Amplitude (height above rest) Amplitude (how tight of compression) Wavelength (crest to crest or trough to trough) Wavelength (comp. to comp. or rare. to rare.) crest compression rarefaction amplitude wavelength amplitude trough wavelength

Think about it Look at the diagram on the right, and make a hypothesis and a diagram that explains how sound waves are interpreted by our brains? Think about the structure of sound waves, and look at the names of the parts of the ear on the right to give you a clue….

Exit Ticket Which wave has the longest wavelength? Which wave has the highest frequency? Which wave carries the most energy? Which wave carries the least energy? What is the frequency of each series of waves in diagrams A, B, and C?

Which wave has the largest amplitude? Which wave carries the least amount of energy? A B

8. What is the amplitude of the wave? 9. What is the frequency? (km)